Chronic diffuse sclerosing osteomyelitis (CDSO) is a condition of unknown aetiology which causes sclerosis, predominantly in the long bones and mandible of young women. We report the cases of three women treated with the intravenous bisphosphonate ibandronate, a new treatment for the disease, and discuss the relevance of the bone marker changes seen in these patients.

Case one is a 27 year old woman diagnosed with CDSO at age 21, when she presented with severe and intractable pain in the left thigh. An x ray examination and magnetic resonance imaging confirmed diffuse cortical thickening with reduced medullary cavity, and bone biopsy confirmed the diagnosis.

Treatment with oral risedronate caused rapid but temporary improvement. She then received three infusions of 2 mg ibandronate over 3 months, with immediate symptomatic relief.

Case 2 is a 38 year old woman with a 10 year history of pain …